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Acquiring Displacement data through an NI 9234

I would like to simultaneously gather data from a PCB force sensor and a displacement sensor through an NI-9234. 

 

I already successfuly acquire data through a PCB force sensor through the 9234 DAQ. However, I am not sure if it would be possible to gather linear displacement data as well. Are there any sensors, such as LVDT's or eddy current probes, that would work with an NI 9234?

 

Thank you.

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Generally, the 9234 can measure voltages or IEPE sensor data with bandwidth up to 23 kHz.

 

Do you need to measure static or dynamic displacement? The required frequency bandwidth and some additional information about the system would help to make a better sensor recommendation.

 

If it is appropriate to your measurement requirements, you could measure velocity or acceleration and integrate to obtain displacement.

Doug
NI Sound and Vibration
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I would like to measure dynamic displacement. To add some background information, I am trying to assemble an apparatus that can measure the loss tangent (tan delta) of a material. Do accomplish this, a sample of the material can placed in between two plates, and a cyclic compressive displacement can be applied to the top plate. The frequency of this displacement is roughly between 1 Hz and 3kHz. A force sensor is placed under the bottom plate to measure the transmitted forces. During this process, the waveforms of the force and displacement are typically analysed, and the phase difference is calculated.

 

I am considering using an accelerometer from PCB and performing numerical integrations as well. If my professor agrees, I could even compare the acceleration and force curves, since the acceleration and displacement waveforms should theoretically have zeros at the same time points.

 

However, in the meantime, I would like to explore the option of using displacement measurement as well. In your professional experience, have you encountered sensors capable of doing the job?

 

Thank you very much for your help.

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A usual impedance measurering head is build of an accelrometer and a force sensor......

However you can replace the accelerometer with a displacement sensor IF you have a reference surface...

I assume about 5-10% uncertaincy , not more than 2mm distance ...  (OK both values should be smaller 😉 😄 )   Nice sensors are laser triangulation ( µEpsilon, Keyence)  distance sensors ... but it's hard to tell without more specs...    LVDTs with 3 kHz dynamic range where rare at the time I used them....

 

 

Greetings from Germany
Henrik

LV since v3.1

“ground” is a convenient fantasy

'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'


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If the material is metal/conductive, you could use an eddy current proximity probe to measure relative displacements. These prox probes require external excitation and are typically a better fit for a module such as the 9232 because these sensors produce a high DC offset (gap voltage) that is interesting for gapping the sensor correctly.

Doug
NI Sound and Vibration
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